Check if user input for date ranges has been made in consecutive, chronological pairs-CodePudding

With PyWebIO I have created a user form that takes up to six dates, each pair composing a date range from start date sdt to end date edt. The first two dates are required, the remaining four are optional. This form can be validated via a function; check_form in my example.

I would like to use this function to allow the user only the input of consecutive, chronological pairs.

Example form:

from pywebio import *

form = input.input_group("form", [
    input.input("Period 1 - Start",
        name="sdt_1",
        type=input.DATE,
        required=True),
    input.input("Period 1 - End",
        name="edt_1",
        type=input.DATE,
        required=True),
    input.input("Period 2 - Start (optional)",
        name="sdt_2",
        type=input.DATE),
    input.input("Period 2 - End (optional)",
        name="edt_2",
        type=input.DATE),
    input.input("Period 3 - Start (optional)",
        name="sdt_3",
        type=input.DATE),
    input.input("Period 3 - End (optional)",
        name="edt_3",
        type=input.DATE),
    ], validate = check_form)

PyWebIO sorts the input into a dict, using the name as key and the input as value.

Output of print(form):

form = {
    'sdt_1': '2020-01-01',
    'edt_1': '2020-08-08',
    'sdt_2': '2021-01-01',
    'edt_2': '2021-08-08',
    'sdt_3': '2023-01-01',
    'edt_3': '2023-08-08'
}

I have come up with a solution that checks for chronological order and for an equal amount of entries. However, this solution still allows the user to make nonsensical input, such as only entering a date for sdt_1, edt_1, sdt_3, sdt_3 or sdt_1, edt_1, sdt_2, edt_3

def check_form(data):
    data_lst = []
    for key in data.keys():
        if data[key] != "":
            data_lst.append(data[key])
    if sorted(data_lst) != data_lst:
        return ("sdt_1", "ERROR: Entries not in chronological order.")
    if len(data_lst) % 2:
        return ("sdt_1", "ERROR: Uneven amount of entries.")

Any help is much appreciated!

CodePudding user response：

Since the first pair is required and the remaining two pairs are optional, you should enforce that logic.

def check_form(data):
    required_pairs = {1} # Specify all the required pairs in this set
    max_pairs = 3        # Max numbber of pairs
    data_lst = []
    for i in range(1, max_pairs 1):
        s_key = f"sdt_{i}"
        e_key = f"edt_{i}"

        # Get the data from the dict. If the key doesn't exist, treat it as an empty string
        s_val = data.get(s_key, "")
        e_val = data.get(e_key, "")

        if i in required_pairs or s_val or e_val:
            if i in required_pairs: 
                # This is a required pair and input is missing
                if not s_val: return (s_key, "ERROR: Missing required input")
                elif not e_val: return (e_key, "ERROR: Missing required input")
            elif e_val and not s_val:
                # e_key is specified but not s_key
                return (s_key, "ERROR: Uneven pair of inputs")
            elif s_val and not e_val:
                # s_key is specified but not e_key
                return (e_key, "ERROR: Uneven pair of inputs")
            
            # We didn't return an error, so this data must be valid
            data_lst.append(data[s_key])
            data_lst.append(data[e_key])

    if sorted(data_lst) != data_lst:
        return ("sdt_1", "ERROR: Entries not in chronological order")

Note that you can check if a string s is empty by simply if s (empty strings are falsy)

Let's test this:

##### VALID INPUTS:
# Case 1: Specify all inputs
assert check_form({
    'sdt_1': '2020-01-01',
    'edt_1': '2020-08-08',
    'sdt_2': '2021-01-01',
    'edt_2': '2021-08-08',
    'sdt_3': '2023-01-01',
    'edt_3': '2023-08-08'
}) == None

# Case 2: Specify only required inputs
assert check_form({
    'sdt_1': '2020-01-01',
    'edt_1': '2020-08-08',
    'sdt_2': '',
    'edt_2': '',
    'sdt_3': '',
    'edt_3': ''
}) == None

# Case 3.1: Specify required inputs and one optional input
assert check_form({
    'sdt_1': '2020-01-01',
    'edt_1': '2020-08-08',
    'sdt_2': '2021-01-01',
    'edt_2': '2021-01-08',
    'sdt_3': '',
    'edt_3': ''
}) == None

# Case 3.2: Specify required inputs and one optional input
assert check_form({
    'sdt_1': '2020-01-01',
    'edt_1': '2020-08-08',
    'sdt_2': '',
    'edt_2': '',
    'sdt_3': '2021-01-01',
    'edt_3': '2021-01-08',
}) == None


#### INVALID INPUTS
# Case 4.1: Skip required inputs
assert check_form({
    'sdt_1': '',
    'edt_1': '2020-08-08',
    'sdt_2': '2021-01-01',
    'edt_2': '2021-08-08',
    'sdt_3': '2022-01-01',
    'edt_3': '2022-01-08',
}) == ('sdt_1', "ERROR: Missing required input")

# Case 4.2: Skip required inputs
assert check_form({
    'sdt_1': '2020-01-01',
    'edt_1': '',
    'sdt_2': '2021-01-01',
    'edt_2': '2021-08-08',
    'sdt_3': '2022-01-01',
    'edt_3': '2022-01-08',
}) == ('edt_1', "ERROR: Missing required input")

# Case 4.3: Skip required inputs
assert check_form({
    'sdt_1': '',
    'edt_1': '',
    'sdt_2': '2021-01-01',
    'edt_2': '2021-08-08',
    'sdt_3': '2022-01-01',
    'edt_3': '2022-01-08',
}) == ('sdt_1', "ERROR: Missing required input")

# Case 5.1: Incomplete pair of optional inputs
assert check_form({
    'sdt_1': '2020-01-01',
    'edt_1': '2020-08-08',
    'sdt_2': '',
    'edt_2': '2021-08-08',
    'sdt_3': '2022-01-01',
    'edt_3': '2022-01-08',
}) == ('sdt_2', "ERROR: Uneven pair of inputs")

# Case 5.2: Incomplete pair of optional inputs
assert check_form({
    'sdt_1': '2020-01-01',
    'edt_1': '2020-08-08',
    'sdt_2': '2021-01-01',
    'edt_2': '',
    'sdt_3': '2022-01-01',
    'edt_3': '2022-01-08',
}) == ('edt_2', "ERROR: Uneven pair of inputs")

# Case 5.3: Incomplete pair of optional inputs
assert check_form({
    'sdt_1': '2020-01-01',
    'edt_1': '2020-08-08',
    'sdt_2': '2021-01-01',
    'edt_2': '2021-08-08',
    'sdt_3': '',
    'edt_3': '2022-01-08',
}) == ('sdt_3', "ERROR: Uneven pair of inputs")

# Case 5.4: Incomplete pair of optional inputs
assert check_form({
    'sdt_1': '2020-01-01',
    'edt_1': '2020-08-08',
    'sdt_2': '2021-01-01',
    'edt_2': '2021-08-08',
    'sdt_3': '2022-01-01',
    'edt_3': '',
}) == ('edt_3', "ERROR: Uneven pair of inputs")

# Case 5.5: Incomplete pair of optional inputs
assert check_form({
    'sdt_1': '2020-01-01',
    'edt_1': '2020-08-08',
    'sdt_2': '2021-01-01',
    'edt_2': '',
    'sdt_3': '2022-01-01',
    'edt_3': '',
}) == ('edt_2', "ERROR: Uneven pair of inputs")

# Case 5.6: Incomplete pair of optional inputs
assert check_form({
    'sdt_1': '2020-01-01',
    'edt_1': '2020-08-08',
    'sdt_2': '',
    'edt_2': '2021-08-08',
    'sdt_3': '',
    'edt_3': '2022-08-08',
}) == ('sdt_2', "ERROR: Uneven pair of inputs")

# Case 6.1: Non-chronological inputs
assert check_form({
    'sdt_1': '2020-01-01',
    'edt_1': '2019-08-08',
    'sdt_2': '2021-01-01',
    'edt_2': '2021-08-08',
    'sdt_3': '2022-01-01',
    'edt_3': '2022-08-08',
}) == ('sdt_1', "ERROR: Entries not in chronological order")

# Case 6.2: Non-chronological inputs
assert check_form({
    'sdt_1': '2020-01-01',
    'edt_1': '2020-08-08',
    'sdt_2': '2021-01-01',
    'edt_2': '2022-08-08',
    'sdt_3': '2022-01-01',
    'edt_3': '2022-08-08',
}) == ('sdt_1', "ERROR: Entries not in chronological order")

CodePudding user response：

I have come up with a solution. Put the dict into a list and check from the second index on if the previous index was empty. Like so:

def check_form(data):
    data_lst = []
    data_lst_2 = list(form.values())
    for key in data.keys():
        if data[key] != "":
            data_lst.append(data[key])
    if sorted(data_lst) != data_lst:
        return ("sdt_1", "ERROR: Entries not in chronological order.")
    if len(data_lst) % 2:
        return ("sdt_1", "ERROR: Uneven amount of entries.")
    for item in data_lst_2[1:]:
        if data_lst_2[data_lst_2.index(item) - 1] == "":
            return ("sdt_1", "ERROR: Entries not consecutive.")